Caster system used with wooden or plastic legs for furniture

ABSTRACT

A caster and leg assembly for supporting a piece of furniture on a floor. The assembly includes a caster affixed within a recessed area formed in the bottom of a wooden or plastic furniture leg to create a strong support for the furniture as well as create a good appearance. The caster has at least one spherical roller supported within the housing to allow the furniture to be readily movable omnidirectionally. With one spherical roller, the weight of the furniture acts at the center of the spherical roller. In one embodiment, there are three spherical rollers located equidistant from the vertical center line of the assembly to support the furniture weight equally by the spherical rollers. A glide can be readily attached and detached from the bottom of the caster and, when attached, the glide cup covers the spherical rollers and presents a flat, planar bottom surface.

REFERENCE TO RELATED CASES

This patent application is a continuation-in-part application based uponand claiming priority of U.S. patent application Ser. No. 10/295,666,filed Nov. 15, 2002 and entitled CASTER ASSEMBLY FOR A BED FRAME MEMBEROR FURNITURE and which is, in turn, a continuation of U.S. patentapplication Ser. No. 09/519,725 filed Mar. 3, 2000, now U.S. Pat.6,568,031, issued May 27, 2003.

BACKGROUND OF THE INVENTION

The present invention relates to a caster assembly for a use withfurniture, and, more particularly, to a caster assembly adapted for usewith a wooden or plastic leg of a piece of furniture.

In general, there are many types of furniture casters that are availableand which are affixed or incorporated into the legs of such furniture toenable that particular piece of furniture to be readily rolled from onelocation to another.

Accordingly, the caster assemblies for furniture normally have rotatablerollers to facilitate the movement of the furniture. Such casterassemblies also generally have an elongated stem that interfits into thefurniture. That stem has a central longitudinal axis along which isdirected the weight of the furniture The roller itself is mounted to theassembly within a housing and the roller is rotatably mounted to thathousing to roll about a central axis that is parallel to the plane ofthe floor. The housing is also pivotally mounted to the furniture leg sothat the roller itself can not only rotate about its axis, but thehousing, including the roller itself, can also pivot 360 degrees aboutthe main longitudinal axis of the stem.

The swiveling action or movement is necessary to correctly align theroller for movement in the proper direction, however, such swivelingmovement can be generally difficult to accomplish. For one reason it isapparent that all of the rollers supporting the furniture must becorrectly aligned in order to easily move the furniture. In mostinstances, the rollers are positioned in various directions and it istherefore necessary to align all of the rollers at the initial movementof the furniture. With the weight of many pieces of furniture, there isconsiderable friction acting against the swiveling action of the casterassembly and the problem is aggravated by the need to align some 4-5rollers in order to roll the furniture. Additionally, the roller isoften embedded into an indentation in the carpet that lies along thesurface of the roller and the roller must be moved out of theindentation to swivel. As such, therefore, while the swivel action isnecessary to properly move the furniture, it can be somewhat difficultto get the swivel action to operate easily and thus the initial movementof the furniture is not easy to accomplish, particularly when the pieceof furniture is on carpeting with padding.

The typical conventional caster for use with carpet is a cylindricalmember that contacts the floor at a certain finite distance away fromthe longitudinal, vertical axis of the stem so that the roller can pivotto a position determined by the direction the furniture is being movedand then the roller rotates to make that movement easy to accomplish. Atypical roller caster assembly used on a bed frame is shown anddescribed in U.S. Pat. No. 4,007,502 of Mis. As can be seen in the Mispatent, the roller is offset with respect to the downward force thatacts through a stem and, as will become clear, this typical caster ofMis suffers from certain inherent weaknesses.

Thus, since the contact point between the roller and the floor islocated at an offset dimension from the longitudinal, vertical axis ofthe stem along which the weight of the furniture is directed, a bendingmoment is created based on the weight of the furniture acting downwardlyon the stem and the distance between the location of that force alongthe longitudinal axis of the stem and the point where the rollercontacts the floor to support the frame.

One of the difficulties with such casters, therefore, is that thebending moment created by that offset creates stress on the casterassembly and can cause a premature failure of the caster assembly or thefurniture itself, thereby disabling the entire unit. The problem isaggravated, of course, with legs having increased degrees of weakness,and in particular, with the use of plastic legs as shown and describedin U.S. Pat. No. 3,828,376 of Miller. Accordingly, it would beadvantageous to have a caster assembly that has rollers that providebetter support for the furniture and which do away with the offset thatcauses the bending moment and the premature fracture of essentialcomponents such as the leg of the furniture, thus avoid damaging thefurniture. There are rollers that have ball bearings that may aid in theswiveling of the roller or aid in the rolling motion of the rolleritself but most require the offset and the consequent swiveling actionto operate in moving the furniture.

Other prior art furniture support assemblies have, in fact, utilized aplurality of elements that contact the floor and examples areillustrated in U.S. Pat. No. 1,060,076 of Glowacki and U.S. Pat. No.1,282,396 of Friend. In the aforementioned patents, however, while aplurality of members contact the floor and thus allow the weight to beborne by a plurality of elements, there is a further problem withrespect to the ease of moving such casters as the spherical members areclamped into the housing supporting the particular piece of furnitureand the spherical contact members do not thus freely rotate to allow theready movement of the furniture. Accordingly, in Glowacki, the ballsthat actually contact the floor are clamped tightly into a circular domeand thus are not movable with respect to the dome as the furniture ismoved. Therefore, while the prior art did consider the support of theweight of a piece of furniture on a plurality of contact members, themoving of the furniture was not enhanced and only the idea of a strongsupport was considered and appreciated.

In addition to caster assemblies, there are also glide assemblies thatare mounted to the various pieces of furniture and have a generallyflat, planar bottom contacting the floor. The glide assemblies arepreferably used where the furniture is located on a hard or slipperysurface such as a wood or tile floor and thus the flat bottom does noteasily slip or cause damage to the floor itself. With such flooringsurfaces, the user of a caster having a roller causes unnecessarysliding or rolling as contrasted to the intended use of a rug roller orcaster on a carpeted surface where the friction with the carpet reducesthe mobility of the roller or caster.

Glide assemblies are inherently stronger than caster assemblies sincethe weight of the bed frame using a glide acts along the longitudinalaxis of the glide directly to the point of contact with the floor, andthus, there is no offset from that axis to the point of contact and,hence, no bending moment. In addition, of course, the glide planarsurface allows more surface contact with the floor and thus carries theweight of the furniture over a wider area so as to provide a betterdistribution of that weight. As such, the glide assembly has enhancedstrength and stability over the caster assembly.

A further alternative is with the use of a caster cup that is generallycup shaped that is slid underneath a roller of a caster assemble to aidin slowing the mobility of the caster and to stabilize the piece offurniture, particularly when used on a slippery flooring surface. Thecaster cups, however, are easily displaced from under the roller sincethey are not firmly locked to or attached to the caster assemblies andare thus difficult to maintain in place when the furniture is movedduring the normal use of the furniture. Thus, over time, the caster cupsbecome displaced with respect to the roller and no longer serve theirintended purpose.

As a further problem with many of the aforedescribed caster assemblies,since the caster roller needs to pivot 360 degrees about its verticalaxis, it is very difficult to build the caster assembly into a wooden orplastic leg of the furniture and, therefore, the caster for a wooden orplastic leg is simply screwed into the bottom of a leg by means of athreaded stem and, accordingly, creates a weak point as well as a lessthan pleasing appearance of the caster affixed to the bottom of a leg.

Accordingly, it would be advantageous to have a caster assembly that canbe used with a wooden or plastic furniture leg that can be recessed intothe leg so that the overall appearance is pleasing and the caster fitsin with the exterior contour of the leg. It would also be advantageousto have a caster assembly for a wooden or plastic furniture leg whereinthe caster assembly has a strong connection to the furniture leg andwhere there is no upstanding stem or other member that can introduce aweak point into the leg/caster combination. It would be still furtheradvantageous to have a caster assembly for a wooden or plastic furnitureleg where there is a glide that can be removably affixed to the bottomof the caster so that the user can readily convert the caster to a glideand vice versa.

SUMMARY OF THE INVENTION

Now, in accordance with the present invention, an improved caster andleg assembly is shown that overcomes the difficulties heretoforeexplained. In the present invention, the caster assembly is adapted foruse with furniture having a wooden or plastic leg. The structure of thecaster assembly comprises a housing that is attachable to the wooden orplastic leg of a piece of furniture by interfitting into a recessed areaprovided in the lower end of the furniture leg. By the interfitting ofthe caster into the bottom of a wooden or plastic leg, the combinedcaster and leg assembly can present an overall smooth, streamlinedexterior surface as well as maintain the strength of the support for thefurniture. As a further advantage, the present caster can be added orretrofitted to an existing furniture leg by an owner of the furniture orcan be installed by the original manufacturer of the furniture.

The assembly has a generally vertical elongated axis or centerline suchthat the weight of the bed is transmitted to the housing of the casterand leg assembly generally along the centerline that is centrallylocated with respect to the housing. At the bottom of the caster thereis at least one, and preferably three, spherical rollers that contactthe floor and allow the piece of furniture roll with respect to thefloor for the convenience of moving the furniture from one location toanother location. The spherical rollers are mounted to a housing havinga cavity and a plurality of small spherical balls are freely locatedbetween the housing and the spherical rollers such that each sphericalroller or rollers freely rotate omni-directionally, that is, the rolleror rollers are free to rotate about center points and thus can rotate inany direction. As such, therefore, the spherical roller(s) can rotate inany direction that the user pushes the piece of furniture in relocatingthat piece of furniture and no additional force is needed to commencethe initial movement of the furniture.

In the preferred embodiment, there are at least three spherical rollers,more preferably three spherical rollers, so that the weight of thefurniture and its supported components and weights are distributed atthree contact points with the floor to better distribute the weight andprevent severe indentations in the floor. In addition, the location ofthe rollers is such that they are equidistant from the elongated,vertical central axis or centerline through which the weight of thefurniture acts on the caster and leg assembly and thus, the singlebending moment is eliminated and the structure has enhanced strength andstability. As stated, with the three rollers, each is still mounted to ahousing such that the rollers move freely in any direction and do notneed to be aligned to the direction of movement of the furniture bypivoting about a central axis or centerline. In effect, the need for aswiveling function is completely eliminated.

Accordingly, the caster assembly of the present invention has thestrength of the prior art glide assemblies since the single offset hasbeen eliminated and, of course, the assembly therefore does not need toswivel in order to allow the furniture or bed to be moved in anydirection. With the offset and the need to swivel eliminated, theaforedescribed problems associated with those features are alsoeliminated.

As a further feature of the present caster assembly, a glide is readilyattachable and detachable to convert the caster assembly from a rollercaster to a glide function and vice versa. When attached, the glidealters the function of the caster assembly from a roller caster wherethe rollers are in contact with the floor to a glide function where thecaster assembly is transformed into a glide. Accordingly, the bottomsurface of the glide is a planar surface as in the case of most glidesand the glide is attached and detached without the need for specialtools or equipment. It should be noted, that the bottom surface of theglide is referred to as planar, however, typically it is an effectiveplanar surface as there is normally a central portion of the bottomsurface that is displaced upwardly and only a peripheral planar area isactually in contact with the floor. The attachment and detachment can bereadily accomplished in the home by an installer that can determine atthe time of installation whether or not the glide or roller function isapplicable.

The resulting caster assembly therefore combines the strength of theglide assemblies with the mobility of a roller caster assembly andprovides the user with the option of using the spherical rollers tocontact the floor or easily transform the caster assembly to add a glideso that the assembly can be used on slippery surfaced floors.

In such situation, instead of changing the caster itself, the user onlyneeds to attach the glide to the bottom of the caster housing whereuponthe rollers are hidden and the lower surface of the caster assembly is aflat surface and therefore suitable for a hard wood or other slipperysurface floors. The glide is locked on to the caster housing and doesnot become detached during the use or movement of the furniture.

In one embodiment the attaching and detaching of the glide isaccomplished by an interfitting of the glide to a lower shroud that ispositioned at the lower portion of the caster assemble. That lowershroud itself has a plurality of elongated openings generally formed asarcs of a circle with a larger opening portion and a smaller openingportion. The glide has a similar number of upwardly directed tabs thatare adapted to fit into the larger post of the openings in the lowershroud. Each of the tabs has an upper lip that is dimensioned to fitthrough the larger opening portion of the elongated openings but whichcannot fit through the smaller opening portions. A locking projection isformed on each of the elongated openings to securely lock the upwardlydirected tabs to the lower shroud.

By simply rotating the glide, the tabs are rotated to a position wherethe tabs are moved into the smaller opening portions where the lips arecaptured by the lower shroud since the lips cannot pass through thesmaller portion openings and the glide is securely retained in positionaffixed to the lower shroud. By such means, the glide is locked intoposition onto the lower shroud of the caster assembly and will not comeapart while the furniture or bed is being used or even during movementthereof. Once affixed to the lower shroud, the glide thus converts thecaster assembly to a glide function, however, even then, the weight isstill distributed through the three spherical rollers that bear againstthe glide and carry the weight of the furniture.

Other features of the caster assembly will become more apparent in lightof the following detailed description of a preferred embodiment thereofand as illustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a conventional bed frame with which thepresent invention can be employed;

FIG. 2 is a side plan view of a typical prior art caster assembly usedin current bed frames;

FIG. 3 is a perspective view of a glide that is also currently used inpresent bed frames;

FIG. 4 is an exploded perspective view of a caster assembly constructedin accordance with the present invention;

FIG. 5 is a bottom plan view of the caster assembly of FIG. 4;

FIG. 6 is a side cross-sectional view of the caster assembly constructedin accordance with the present invention;

FIG. 7 is a side cross sectional view of the caster assembly having theglide component attached thereto;

FIG. 8 is a perspective exploded view of the preferred embodiment of thecaster assembly of the present invention;

FIG. 9 is a bottom perspective view of an upper shroud component of thepreferred embodiment of the present invention;

FIG. 10 is a side cross sectional view of a stem housing component ofthe preferred embodiment;

FIG. 11 is a top perspective view of the component of FIG. 10;

FIG. 12 is a bottom perspective view of the component of FIG. 10;

FIG. 12A is a bottom plan view of the component of FIG. 10;

FIG. 13 is a top perspective view of the ball cup component of thepreferred embodiment;

FIG. 14 is a bottom perspective view of the ball cup component of FIG.13;

FIG. 15 is a side cross sectional view of the component of FIG. 13;

FIG. 16 is a top perspective view of the lower shroud component of thepreferred embodiment;

FIG. 17 is a top perspective view of a glide cup component of thepreferred embodiment;

FIG. 18 is a side view of the component of FIG. 17;

FIG. 19 is a side cross sectional view of the preferred embodiment ofthe caster assembly of the present invention;

FIG. 20 is a perspective view of bed rails connecting between aheadboard and a footboard including a cross member;

FIG. 21 is a perspective view of a caster assembly of the presentinvention adapted to be used with the side rail construction of FIG. 20

FIG. 22 is a perspective view of a couch utilizing the caster assembliesof the present invention;

FIG. 23 is a cross sectional view of a caster assembly of the presentinvention fitted into a wooden of plastic leg for use with furniture;

FIG. 24 is a cross sectional view of a still further embodiment of thecaster assembly of the present invention;

FIG. 25 is a cross sectional view of a further embodiment where only onespherical roller is used;

FIG. 26 is a perspective, cutaway view of a box spring showing theaffixation of a caster thereto;

FIG. 27 is a side view of a caster affixed in the manner illustrated inFIG. 26;

FIG. 28 is a perspective view of a box spring illustrating a furthermeans of affixing a caster to a box spring; and

FIG. 29 is a perspective view of a caster that is used in the affixationmeans illustrated in FIG. 28.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to FIG. 1, there is shown a perspective view of aconventional bed frame with which the present invention can be applied.It should be noted, however, that while the FIG. 1 embodiment of thepresent invention is initially shown and described specifically for usewith a bed frame, the broader aspects of the invention make itapplicable to any item of furniture with the same advantages andimprovements.

Thus, in FIG. 1, the conventional bed frame is comprised of a pair ofside rails 10 and cross members 12. The number of cross members may varydepending upon the particular bed, and its size, that is, there may beone or more intermediate cross members that provide additional supportto the box spring and mattress when assembled. The side rails 10 andcross members 12 are normally constructed of L-shaped angle iron. Asshown, there are legs 13 that are normally located on the cross members12 or the side rails 10 depending on the particular construction and, ifany further cross members are used in the bed frame, there may also beone of more additional legs extending downward from those cross members.At the bottom of the legs 13, there are affixed thereto casters 14 thatare in contact with the floor.

Taking now FIGS. 2 and 3, there is shown, respectively a side view of atypical caster 14 and a perspective view of a typical glide 16. Eitherthe caster 14 or the glide 16 can be used as a support for a bed frameand each is preferably used in differing circumstances. Taking first thecaster 14, as can be seen, the conventional caster comprises a roller 18that is normally cylindrical and which rotates about an axis, indicatedby the letter A, that is positioned parallel to the floor. The caster 14includes a metal housing 20 having an upstanding stem 22 that extendsupwardly and which is inserted into the leg or other support point onthe piece of furniture.

The roller 18 thus rolls freely about its axis A in the direction at aright angle to that axis, however, the roller 18 obviously does notfreely rotate to move the piece of furniture or bed frame if the userattempts to move that furniture in the direction along the axis ofrotation of roller 18. To accomplish moving the furniture in suchdirection, therefore, it is necessary for the housing 20 to swivel aboutthe axis B of the upstanding stem so that the roller 18 becomes alignedwith the proper path of travel. As will be later explained, in order forthe housing 20 to swivel there is a necessary offset between the axis Band the point of contact of the roller 18 with the floor.

In the normal movement of the caster 14, the swiveling movement takesplace quite automatically as the furniture, such as a bed, is moved inthe desired direction since the swivel effect takes place as the initialmovement occurs and the roller 18 becomes aligned properly for thatdirection of movement. As explained, however, the swiveling action canbe difficult to accomplish and the initial movement of the furnituretherefore is not easily facilitated.

In addition to the swiveling problem, the normal caster, as shown inFIG. 2 also suffers from an inherent weakness in that the weight of thefurniture is directed downwardly along the axis B of the upstanding stem22 whereas the contact with the floor and the support point for thefurniture occurs at the point 24 at the bottom of the roller 18. As canbe seen, there is an offset or finite distance between the direction ofthe load imposed by the furniture along the axis B and the point atwhich that load is supported by the floor. That offset is necessary toaccomplish the swiveling action, however, it also sets up a stress inthe caster by creating a bending moment in the caster 14 that is alwayspresent and can lead to premature failure of the caster 14 and/or theconnecting leg.

Accordingly, while the caster 14 is certainly helpful in providingmobility to the piece of furniture, there are inherent weaknesses thatcan lead to a failure of the caster or the leg of the bed frame itselfthat are always present due to the basic design of the caster and canlead to the possibility of damage to the caster or other structuralcomponents of the bed frame.

Turning to FIG. 3, a glide 16 is shown and which is also used withfurniture as a support, particularly where the piece of furniture islocated on a hardwood or tile floor. Again, the glide 16 includes anupstanding stem 26 that is adapted to be inserted into the leg or othersupport point of the furniture. The glide 16 has a flat bottom surface28 and is thus preferred on the aforementioned floors and, unlike thecaster 14, is exceptionally strong since the weight of the furnitureacting downwardly along the main axis of the upstanding stem 26 isdirectly supported by the contact with the floor and there is thereforeno offset to that force that can cause stress. The glide is typicallyused on a bed rail assembly and can be used on carpeted floor forstrength, however the added friction between the bottom of the glide andthe carpeted floor make the potential of damage to the bed structuremore likely.

On the other hand, of course, with the use of glide 16, the mobility ofthe furniture is sacrificed. Not only is the mobility of the furnituresacrificed, but there is an additional weakness in the glide 16 if thefurniture is attempted to be moved since the glide 16 does not movereadily along a carpet, for example, and any attempt to slide thefurniture along that type of flooring can cause the glide to get caughton the material and cause the glide to snap off from the upstanding stem26 or worse, to break off a leg or other part of the furniture. This isparticular true where the glide is positioned at the center of a bedframe affixed to a cross member since that location is already arelatively weak structure and is subject to bending and breaking.

Therefore, since the present caster assembly 30 does not need to swivelin order to allow the piece of furniture to be moved, as was the casewith the prior art rollers, the present caster assembly 30 can beaffixed to the piece of furniture in a wider variety of ways, such asbeing attached offset to the side of the furniture as the center of thecaster assembly 30 need not be the particular point of the casterassembly that is actually affixed to the furniture. With the prior artswivel casters, particularly those screwed into the furniture, suchversatility was not present and the means and location of attachment tothe furniture was limited.

Turning now to FIG. 4, there is shown an exploded view of a casterassembly 30 constructed in accordance with the present invention. In theFigure, the caster assembly 30 includes an upstanding stem 32 thatagain, is adapted to enter and be secured to the particular piece offurniture to which the caster assembly 30 is attached. As noted, thestem 32 will be described that interfits with a leg of a bed frameassembly, however, the stem 32 may have a flat flange at its upper pointwith suitable holes so that the caster assembly can be secured to apiece of furniture by means of wood screws or other securing means. Ahousing 34 is provided and from which the upstanding stem 32 extends andwithin which is positioned a plurality of spherical rollers 36. In thepreferred embodiment, and as is shown in FIG. 4, three spherical rollersare utilized. Each of the spherical rollers 36 extend downwardlyexternal of the housing 34 and, as such, contact the floor when inposition supporting a piece of furniture.

In this embodiment, the spherical rollers 36 can be formed of plasticmaterial, particularly a plastic having good lubricity and a goodmemory, one example of which is available commercially from the DuPontCompany under the trademark DELRIN. That same material can be used forother components of the caster assembly 30 such as the housing 34. Aglide cup 38 is also provided that is readily attached and detached fromthe housing 34 so that the contact with the floor can be by means of thespherical rollers 36 or, at the option of the user, by contact with theflat, planar bottom 40 of the glide cup 38. The glide cup 38 can also bemade of the same plastic material as previously described.

In order to allow the glide cup 38 to be readily attached and detachedto the housing 34, there is provided at the lower perimeter of thehousing 34, at least one projection 42 that extends outwardly from thelower perimeter. Again, in this embodiment, there are a plurality ofsuch projections 42 extending from the housing 34. Glide cup 38 has anupstanding flange 44 having formed therein, an internally facing ridge46 with a plurality of recesses 48 that dimensionally coincide with theprojections 42 on the housing 34. Thus when the glide cup 38 is to beattached to the housing 34, the glide cup 38 is positioned over thelower periphery of the housing 34 and the projections 42 fit through therecesses 48 so that the glide cup 38 can be fully moved over the lowerperiphery of the housing 34.

The projections 42 thus pass through and clear the internally facingridge 46 after passing through the recesses 48 such that the glide cup38 can be simply rotated a predetermined amount and lock the projections42 behind the internally facing ridge 46 so that the glide cup 38 issecurely attached to the housing. In the position with the glide cup 38attached to the housing, the caster assembly 30 acts as a glide and thespherical rollers 36 are contained within the glide cup 38. As isobvious, therefore, the glide cup 38 can, by another predeterminedrotation, be just as easily detached from the housing 34 so that thespherical rollers 36 can contact the floor.

When the glide cup 38 is installed, the spherical rollers 36 touch andactual bear on the upper surface of the glide so that, in use, theweight of the bed or other furniture is distributed through thespherical rollers 36 to the glide cup 38 such that the weight of thefurniture is well distributed to the glide cup 38 and there is no weightacting on any of the projections 42 or other likely breakablecomponents.

The spherical rollers 36, as can be seen, preferably have centers ofrotation and thus are free to rotate omni-directionally, that is, in anydirection about their center point of the spherical shape. In addition,in the preferred embodiment, the centers of the spherical rollers 36 arepositioned equidistant from the main axis of the upstanding stem 32 sothat the weight of the furniture that acts along the main axis of theupstanding stem 32 is equally distributed among the spherical rollers 36in their contact with the floor. With the weight distribution equallydivided, the overall weight is borne by the main axis of the casterassembly 30 and thus through the strength of the assembly. Accordingly,the present caster assembly 30 provides the mobility of the prior artcasters while having the strength and structural integrity of the priorart glides. In addition, with the addition of the glide cup 38 thecaster assembly 30 can also have the non-marring flat planar surface tocontact the floor whenever desired and without difficulty.

Turning now to FIG. 5, there is shown a bottom plan view of the casterassembly 30 constructed in accordance with the present invention andwith the glide cup 38 not attached thereto. In this Figure, the physicallayout of the spherical rollers 36 can be further explained. Inparticular, the main, longitudinal axis of the upstanding stem (notshown in FIG. 5) is at the center point 50 of the caster assembly 30 andthe weight of the furniture is therefore concentrated along that axisand therefore acting downwardly at about the center point 50. Also shownare the center points 52 of the spherical rollers 36. Thus, it can beseen that the center points 52 of the spherical rollers 36, in thepreferred embodiment, are all equidistant from the main longitudinalaxis of the upstanding stem so that the weight of the furniture isequally distributed among the three spherical rollers 36 and along thecenter and the structural strength of the caster assembly 30.

Turning next to FIGS. 6 and 7, there is shown, respectively, a sidecross sectional view of the caster assembly 30 without the glide cup 38attached and a side cross sectional view with the glide cup 38 attached.The spherical rollers 36 may be provided in commercially availableself-contained cartridges 54 that can be inserted into suitably shapedholes 56 formed in housing 34. In order to allow the spherical rollers36 to freely rotate about their center points 52, a plurality of smallspherical balls 58 are freely position within the cartridges 54 andfreely movable within an annular recess 59 and which allow the sphericalrollers 36 to be able to rotate in any direction readily and with aminimum of friction. While a annular recess 59 is shown, the sameomni-rotation of the spherical rollers 36 can be accomplished, albeitless efficiently, without the use of the annular recess 59 such that thesmall spherical balls 58 are simply located at the upper surface of thespherical rollers 36. In a still further less efficient construction,the small spherical balls 58 can be eliminated altogether. Suchmechanisms are readily available commercially including the sphericalrollers contained within a housing with small spherical balls freelyfloating intermediate the housing and the spherical rollers 36 to allowthe spherical rollers 36 to freely rotate about their center points inany direction, that is, omni-directionally.

In FIG. 7, the addition of the glide cup 38 can be seen with theinternally facing ridge 46 locked in position behind the projections 42so that the glide cup 38 is securely affixed to the housing 34 and thespherical rollers 36 are covered by the glide cup 38 and out ofoperational use.

Turning now to FIG. 8, there is shown a perspective, exploded view ofthe preferred embodiment of the caster assembly 70 of the presentinvention and in view of a later more detailed description of theindividual components, a brief description of those components will beinitially discussed and new designation numbers assigned even thoughmany components are the same as or similar to the components used in theprior embodiments.

Accordingly, as shown in FIG. 8, there is a spindle 72 that, asexplained, is used to affix the caster assembly 70 to the particularpiece of furniture. Atop of the spindle 72 is positioned a bushing 74that is preferably of a plastic material such as polypropylene. Thebushing 74 enables the caster assembly 70 to be inserted into the femaleopening normally provided in furniture, including bed frames and thestructural members that make up beds in general. The bushing 74 ispressed onto the spindle 72 and is thus held thereto by an interferencefit. By convention, the components will also be referred to as upper andlower throughout and such reference shall be intended to denote theupper direction as toward the piece of furniture and the lower directionto be towards the floor on which the furniture is supported. By thatconvention, therefore, the bushing 74 is positioned on the upper portionof the spindle 72 and the lower portion of the spindle 72 extendsthrough an upper shroud 76 through an opening 78.

The lower portion of the spindle 72, when assembled, further passesthrough a central bore 80 formed in a stem housing 82. As will be seen,the spindle 72 is in an interference fit in the central bore 80 suchthat the stem housing 82 is pressed on to the spindle 72 to affix thespindle 72 firmly to the stem housing 82. The spindle 72 continues withits lower end fitted, again, in an interference fit, into the bore 84 ofa ball cup 86. A plurality of spherical rollers 88 are fitted within theball cup 86 by a snap fit as will be explained and a plurality ofsmaller balls 90 are located atop of the spherical rollers 88 to aid inthe omni-directional rotation of those spherical rollers 88.

Beneath the spherical rollers 88, there is positioned a lower shroud 92and which is affixed to the upper shroud 76 by means such as drivescrews 94. Finally, as shown in the FIG., there is a glide cap 96 thatis removably affixed to the lower shroud 92 so as to be easily attachedand detached from the lower shroud 92.

Turning now to FIG. 9, taken along with FIG. 8, there is shown a bottomperspective view of the upper shroud 76 and which has in its interior aplurality of locating ribs 98 and bosses 100 that extend downwardly toreceive the drive screws 94 when the lower shroud 92 is affixed to theupper shroud 76. In addition, as can be seen, there is an annular flange102 that extends downwardly into the interior of the upper shroud 76 andwhich has a plurality of slots 104 formed therein. In the preferredembodiment, the upper shroud 76 is formed of a molded plastic materialsuch as polypropylene.

With reference to FIG. 10, taken along with FIG. 8, there is shown aside cross sectional view of the stem housing 82. In that Fig. thecentral bore 80 can be seen through which the lower portion of thespindle 72 passes in an interference fit in affixing the spindle 72 tothe stem housing 82. As also can be seen, the is a spherical indentation106 formed in the lower surface of the stem housing 82 having apredetermined radius and center point and an annular recess 108extending upwardly from the lower surface of the stem housing 82 andsurrounding the spherical indentation 106. As shown, of course, thereare preferably three spherical indentations 106 that conform to thepreferred number of spherical rollers 88 employed in the preferredembodiment. In addition, there is formed in the stem housing 82, aplurality of upwardly directed bosses 110, having internal bores 112,the purpose of which will be later explained.

Turning now to FIGS. 11, 12 and 12A, taken along with FIG. 8, there isshown, respectively, a top perspective view, a bottom perspective viewand a bottom plan view of the stem housing 82. In FIG. 11, there can beseen, a plurality of ribs 114 extending outwardly from the central bore80 and which preferably comprise three ribs 114 wherein the upper edges116 of such ribs 114 fit into the slots 104 (FIG. 9) of the upper shroud76 when the overall caster assembly 70 is assembled into a completedunit. As further shown in FIG. 11, the upwardly directed bosses 110comprise three bosses 110 and the internal bores 112 of those bosses 110are dimensioned so as to receive the bosses 100 of the upper shroud 76(FIG. 8), again, when the overall caster assembly 70 is assembled.Further enlarged bores 118 are formed in the stem housing 82 along theinternal bores 112 in the lower surface of the stem housing 82 (FIGS. 10and 12) and are also utilized to allow the overall caster assembly 70 tobe compactly and sturdily assembled together into the completed unit. InFIG. 12A, there can be seen the lower portion of the annular recess 108and illustrating that the annular recesses 108 are annular and fullycircular in form and are located between the outer edges 105 of thespherical indentations 106 and the inner diameter 107 within the innerhousing 82.

Turning now to FIGS. 13 and 14, taken along with FIG. 8, there is shown,a top perspective view and a bottom perspective view, respectively, ofthe ball cup 86 of the present invention. There is thus shown, the bore84 within which the lower end of the spindle 72 terminates in aninterference fit upon assembly. Surrounding the bore 84 are openings 120that, as will be seen, contribute to the overall compactness of thecompleted assembly. Three circular flanges 122 extend downwardly fromthe ball cup 86 and contain the spherical rollers 88. The internalcavity 124 of those circular flanges 122 is formed in a generallyspherical configuration and includes a circular ridge 126 that is usedto contain those spherical rollers 88 in a snap fit. As seen, withreference to FIG. 13, the upper peripheral surface 128 surrounding eachof the internal cavities 124 is slightly chamfered inwardly in a gentlysloping surface leading into the internal cavities 124. Slightly raisedflanges 130 partially surround the upper periphery of the internalcavities 124.

Turning to FIG. 15, there is shown a side cross sectional view of theball cup 86 such that one of the internal cavities 124 can be seen withthe internal spherical configurations. As will be seen, theconfiguration and the dimensions of the spherical internal cavity 124 assuch that the spherical rollers 88 can simply be snapped into thoseinternal cavities 124 and retained in that position where the sphericalrollers 88 are contained but can freely rotate in any direction, thatis, omni-directionally. In the preferred embodiment, the sphericalrollers 88 are comprised of an acetal plastic material.

Next, in FIG. 16, taken with FIG. 8, there is shown a top perspectiveview of the lower shroud 92 and which has its external peripheralsurface mate with the external peripheral surface of the upper shroud 76to contain the components of the completed caster assembly 70. In thisFIG., the lower shroud 92 includes three bosses 132 that extend upwardlyand, when the caster assembly 70 is assembled, the bosses 132 extendthrough the openings 130 of the ball cup 86 (FIGS. 13 and 14) to contactand fit into the enlarged bores 118 of the stem housing 82 (FIGS. 11 and12). The lower shroud 92 also includes a plurality, (preferably three)of openings 134 having circular flanges 136 that extend upwardly andthrough which the circular flanges 122 of the ball cup 86 pass (FIG. 14)in the assembly of the overall caster assembly 70.

In the lower surface 138 of the lower shroud 92, there is formed aseries (three) of elongated slots 140 having a longitudinal axis forminga circular arc. As can be seen, the elongated slots 140 comprise alarger width portion 142 and a smaller width portion 144 about thatarced configuration. In addition, there are small projections 145 formedat the entrance to the smaller width portions 144 that extend slightlyinto the elongated slots. The purpose for the elongated slots 140 willbecome apparent from a discussion of the next Figures.

Thus, turning to FIGS. 17 and 18, taken along with FIG. 8, there isshown a top perspective view and a side view of the glide cap 96 that isused with the present invention. As explained, the glide cap 96 isdesigned to be easily affixed to and removed from the overall casterassembly 70 to convert the caster assembly 70 between its differentfunctions of action as a roller assembly and a glide assembly.

Thus, in FIGS. 17 and 18, there is a lower surface 146 that is generallyplanar and is adapted to contact the floor when the glide cap 96 isinstalled with the caster assembly 70. A plurality of tabs 148 aremolded into the glide cap 96 and which, itself is preferably a plasticmolded polypropylene material. Again, the preferred number of tabs 148,as shown, is three. At the upper end of the tabs 148, three are formedlips 150 that are directed outwardly with respect to the center of theglide cap 96.

Thus, returning to FIG. 16, taken along with FIGS. 17 and 18, theinteraction of the tabs 148 and the elongated slots 140 can beexplained. In affixing the glide cup 96 to the lower shroud 92, the tabs148 align with the larger width portions 142 of the elongated slots 140in the lower surface 138 of the lower shroud 92 such that the glide cup96 can be positioned to insert those tabs 148 through the larger widthportions 142. Thereafter, by merely rotating the glide cup 96, the tabs148 can enter the smaller width portion 144 where the lips 150 arecaptured by the lower surface 138 of the lower shroud 92. The smallerwidth portions 144 prevent the passage of the lips 150 therethrough andthus the glide cup 96 is readily and easily retained to the lower shroud92 so that the caster assembly 70 acts as a glide. As the tabs 148 passby the small projections 145, the tabs 148 are effective locked intoposition and do not readily become detached by normal use of the bed ormovement thereof. Obviously, the removal of the glide cup 96 is just aseasily accomplished by a reversal of the process, that is, the glide cup96 is rotated to the position where the tabs 148 are in alignment withthe larger width portions 142 so that the lips 150 can pass through theelongated slots 140 and the glide cup 96 removed.

Taking FIG. 19, there is shown a side cross sectional a view of thecompleted and assembled caster assembly 70. In the FIG., therefore, itcan be seen that the spherical rollers 88 are fitted into the ball cup86 and are freely rotatable therein omni-directionally and the pluralityof smaller balls 90 freely move within the annular recess 108 to allowthe movement of the spherical rollers 88. Those smaller balls 90 moveover the upper surface of the spherical rollers and are contained withinthe area between the spherical rollers 88 and the spherical indentations106 in the stem housing 82. In the assembled form, as shown in thisFIG., therefore the drive screws 94 affix the lower shroud 92 to theupper shroud 76 to encase all of the components in the overall casterassembly 70 in accordance with the present invention. Alternatively, ofcourse, in the place of drive screws 94, other means could be used, suchas self tapping, thread cutting screws.

Turning now to FIG. 20, there is shown a perspective view of bed rails60 connecting between a headboard 62 and a footboard 64 and showing across member 66. As can be seen, with the use of bed rails 60, thevertical height of the bed rails 60 above the floor is not a standarddimension and depends on the height of the legs of the headboard 62 andthe footboard 64. Accordingly the cross member 66 must have a supportthat is adjustable as to height. In such case, a caster assembly 30 isprovided that supports the center of the cross member 66 and isadjustable in height but still has the advantages as previouslyexplained with respect to mobility and strength of the caster assembly30. The cross member 66 may also be of the type that is universallyadapted for use with bed rails and is further disclosed in a U.S. patentapplication filed on the same day as the present application andentitled UNIVERSAL TENSION SPRING SUPPORT MEMBER FOR BED RAILS OR BEDFRAME, and the disclosure of that application is incorporated herein byreference.

Thus, turning to FIG. 21, there is shown a perspective view of a casterassembly 30 that is adjustably affixed to the leg extending downwardlyfrom the cross member 66 so as to contact the floor and provide supportto the overall completed bed. Thus, in this embodiment, the upstandingstem 32 is threaded at 68 and is screwed into a corresponding internallythreaded opening in the leg of the cross member 66. This embodiment isnot, however, the preferred embodiment. The preferred embodiment is toaffix the caster assembly to the furniture by means of a plastic bushingshown in FIG. 8 that is press fitted into the suitable opening in thepiece of furniture. As stated, since the caster has considerablestrength, it can be used in place of a conventional glide that isnormally used with such cross members and yet the caster assembly 30 isalso mobile and can readily be moved along a bare wood floor or acarpeted floor without suffering the breakage problems associated withthe use of a normal glide.

Turning now to FIG. 22, there is shown a perspective view of a piece offurniture, namely a couch 152, that is supported by caster assemblies154 of the present invention. As can be seen, the weight of the couch152 is directed downwardly upon the caster assemblies 154 to besupported on the floor and, as has now been explained, the couch 152 canthereof be rolled in any direction without the need to align any offsetrollers and thus the rollability of the couch 152 is greatly improvedover the prior art casters used with such furniture. As also should benoted, the overall appearance of the couch 152 is pleasing with respectto the caster assemblies 154 since they blend in both functionally aswell as esthetically with the appearance of the couch 152 since, as willbe later described, the caster assemblies 154 are actually fitted intowooden or plastic legs that support the couch 152.

Next, in FIG. 23, there is a cross sectional view of a combined casterand leg assembly 156 constructed in accordance with the presentinvention. As can be seen, the caster and leg assembly 156 comprises aleg 158 and which is constructed out of wood or a plastic material. Atthe top surface or upper end 160 of the leg 158 there is a threaded stem162 for securing the caster and leg assembly 156 to a piece offurniture, such as the couch 152 of FIG. 22, in order to affix thecaster and leg assembly 156 thereto for supporting the piece offurniture on a floor. At the lower end 164 of the leg 158, there isformed a recessed area 166 that is cut or molded in the lower end 164.

Within the recessed area 166 there is located the caster 168 and which,as has been explained, includes a caster housing 170 that is fitted upinto the recessed area 166 so as to not detract from the externalappearance of the leg 158 as well as to provide a strong support for thepiece of furniture. The caster housing 170 can be affixed within therecessed area 166 by means such as screws 172 whereby the caster 168 iscontained substantially within the recessed area 166 with the sphericalrollers 174 (three spherical rollers 174 are used) extending downwardlyfrom the recessed area 166 in order to contact the flat planar surfaceof the floor 176. There is also a longitudinal, vertical centerline CLshown in FIG. 23 that centers the weight imposed by the furnituredirectly through the caster and leg assembly 156 since the centerline CLis centered with respect to the center points of the spherical rollers174, thereby avoiding the offset and misaligned effect of thedistribution of weight with normal casters used with furniture.

The small spherical balls 178 are also shown to be located within theannular, upwardly extending cup shaped recess 180 formed in the casterhousing 170 so that the spherical balls 178 are free to move in and outof the chamber 182 intermediate the spherical rollers 174 and the uppersurface 184 formed in the caster housing 170. That upper surface 184 hasthe same curvature or a slightly more shallow curvature than theexterior surface of the spherical rollers 174 in order to allow the freemovement of the spherical balls 178 into and out of the chamber 182.

Accordingly, as can now be appreciated, the caster and leg assembly 156provides a very strong support for the furniture since the weight of thefurniture acts directly through the caster and leg assembly 156 withoutany offset between the direction of the weight and the contact with thefloor and yet the caster 168 can be embedded into the wooden or plasticleg used for the furniture.

Turning now to FIG. 24, there is a cross sectional view of a furtherembodiment of the present invention where the wooden or plasticfurniture leg 186 has its upper end 188 affixed to the frame of thefurniture and is part of the furniture such that the recessed area 190formed in the lower end 192 of the furniture leg 186 has been cut intothe furniture leg 186. Thus, in this embodiment, the recessed area 190can be pre-formed by the manufacturer of the furniture and the leginstalled by that manufacturer or, alternatively, the present inventionmay be incorporated into the normal leg of a piece of furniture bycutting or shaping the recessed area 190 in order to retrofit the caster168 of the present invention into an already constructed piece offurniture. Thus, a user already having the piece of furniture with awooden or plastic leg can add the present caster 168 to upgrade thatfurniture and attain the advantages of strength and better appearance byadding the caster 168 of this invention to the leg 186 of the furniture.

Accordingly, the normal furniture leg 186 again holds the caster 168 toproduce the caster and leg assembly 192 illustrated in FIG. 24. As withthe prior embodiment, the longitudinal, vertical axis or centerline CLagain is the direction and location of the acting weight of thefurniture since it is equidistant from the center points of thespherical rollers 174 and therefore the weight of the furniture is notoffset to cause harmful moment arms in the caster and leg assembly 194.

In FIG. 25 there is a cross sectional view of a still further embodimentof the present invention and where there is only one spherical roller174 that is positioned in the caster 168 so as to have its center pointalong the longitudinal, vertical centerline CL of the furniture leg 196so that, as with the prior embodiments, the weight of the piece offurniture acts downwardly along the centerline CL directly, withoutoffset, to the floor 176. In this embodiment, the upper end 198 of thefurniture leg 196 may also be directly affixed to the frame of theparticular piece of furniture and the lower end 200 has formed therein amore narrow recessed area 202. Within that recessed area 202, there isprovided a socket 204 that is affixed therein and which receives a stem206 to affix the caster housing 208 to the furniture leg 196.

Again, the centerline CL of the caster and leg assembly 208 passesthrough the center point of the spherical roller 174 to insure that theweight of the furniture acts directly through the spherical roller 174and not offset as with the conventional offset casters.

Therefore, with the use of the leg and caster assembly of the presentinvention, the support through the leg contacting the floor isstrengthened and yet the overall appearance is enhanced by locating thecaster contiguous to the smooth continual exterior surface of the lowerportion of the furniture leg. In any of the embodiments of FIGS. 23-25,a glide can be attached to the caster housing in the manner shown anddescribed with respect to FIGS. 4 and 7 hereof.

Turning now to FIG. 26, there is shown a perspective, cutaway view of abox spring 210 that has a caster 212 affixed thereto in accordance withthe present invention. As can be seen, the box spring 210 is constructedof a angle iron lower edge 214 that extends around the perimeter of thebox spring 210 forming an inwardly directed ledge that supports thewooden cross beams 216 of the box spring 210. The wooden cross beams 216are also supported by metal T-shape cross supports 218 and a generallyrigid wire structure 220 both stabilizes the inner stuffing 222 andsupports the outer covering 224.

At each corner of the box spring 210 there is provided a plastic corner226 that supports the upper wire 228 of the, rigid wire structure 220and which also rounds off the angle iron lower edges 214 to provide anoverall rounded and pleasing appearance of the box spring 210. At thebottom of the plastic corner 226, there is a threaded hole (not shown).As alternative embodiments, the plastic corner 226 may be constructed ofwood, metal or other suitable materials and instead of a threaded hole,there may be a pilot hole or no hole at all as will be later explained.

Turning to FIG. 27, taken along with FIG. 26, there is a side view ofthe caster 212 used with the FIG. 26 embodiment and where the caster 212can be of the construction previously disclosed and discussed and whichhas a threaded stud 230 extending upwardly therefrom. Therefore, inorder to affix the caster 212 to the bottom of the box spring 210, thethreaded stud 230 is simply screwed into the threaded hole in the bottomof the plastic corner 226.

In the alternative embodiment, if the corner of the box spring 210 iswood, the threaded stud 230 can have wood screw threads and be screwedto the wooden corner by the aid of a small pilot hole or directly intothe wood if there is no hole present at all. In any event, the caster212 is screwed directly to the bottom of the box spring 210.

Turning finally to FIGS. 28 and 29, there is shown, respectively, aperspective view of a box spring 232 illustrating a further method ofaffixing a caster 234 to a box spring 232 and a perspective view of thecaster 234 itself. As such, there is a female receptacle 236 formed inthe bottom of the box spring 232 and, as shown, is in the configurationof a chevron, or L-shaped, that is, two straight portions 238 joined atan angle. The receptacle 236 can be provided as an insert embedded intothe bottom of the box spring 232 or by other means, including, cuttingthe receptacle 236 therein. The internal, outer edges 240 can be taperedinwardly as the height of the receptacle 236 increases upwardly.

In FIG. 29, the male wedge member 242 is shown affixed to the caster 234and which is generally L-shaped and dimensioned to interfit into thefemale receptacle 236. Thus, the external edges 244 of the male wedgemember 242 are tapered outwardly toward the caster 236 in acomplementary way to the inwardly tapered inner edges of the receptacle236. Therefore, the caster 234 is affixed to the box spring 232 bysimply pushing the male wedge member 242 up into the female receptacle236 in the direction shown by the arrow W so that the male wedge member242 is jammed into the female receptacle 236 to retain the caster 234 tothe box spring 232 in a manner to be removable retained thereto. Theaffixation or junction between the caster 234 and the box spring 232 isfurther enhanced by the weight of the mattress and other covers that areplaced atop of the box spring 232 since that weight further pushes themale wedge member 242 strongly into the female receptacle 236.

While the present invention has been set forth in terms of a specificembodiment or embodiments, it will be understood that the casterassembly herein disclosed may be modified or altered by those skilled inthe art to other configurations. Accordingly, the invention is to bebroadly construed and limited only by the scope and spirit of the claimsappended hereto.

1. A caster and leg assembly for supporting a piece of furniturepositioned on a generally planar surface, said caster and leg assemblycomprising a wooden or plastic leg extending downwardly and having alower end with a recessed area formed therein, and a caster affixedwithin said recessed area, said caster having a housing containing atleast one spherical roller, said at least one spherical roller adaptedto contact the generally planar surface for supporting said caster andleg assembly, a plurality of spherical balls located intermediate saidat least one spherical roller and said housing, said spherical ballsadapted to move in a continuous circulatory path within said housing andto enter the area intermediate said at least one spherical roller andsaid housing by means of gravity, wherein said at least one sphericalroller is freely rotatable under load to allow movement of the piece offurniture along the generally planar surface in any direction.
 2. Acaster and leg assembly as defined in claim 1 wherein said caster has acentral vertical longitudinal axis and said at least one sphericalroller comprises one spherical roller having its center point locatedalong said central vertical longitudinal axis.
 3. A caster and legassembly as defined in claim 1 wherein said caster has a centralvertical longitudinal axis and said at least one spherical rollercomprises three spherical rollers having their center points spacedequidistant from said central vertical longitudinal axis.
 4. A casterand leg assembly as defined in claim 1 wherein said assembly issubstantial housed within the recessed area of the leg to create anoverall smooth, contiguous exterior profile of the leg and casterassembly.
 5. A caster and leg assembly as defined in claim 1 wherein theassembly includes a glide having a flat bottom that is attachable to anddetachable from the housing to cover and uncover the at least onespherical roller.
 6. A caster and leg assembly as defined in claim 1wherein the leg is affixed to the piece of furniture.
 7. A caster andleg assembly as defined in claim 1 wherein the leg has a lower surfacehaving a hole formed therein and said housing has a stem extendingupwardly therefrom that interfits into the hole in said leg.
 8. A casterand leg assembly as defined in claim 1 wherein the housing is affixed tothe leg by means of screws.
 9. A method of affixing a caster onto awooden or plastic furniture leg of a piece of furniture, said methodcomprising the steps of: forming a recessed area in the lower end of awooden or plastic furniture leg, providing a caster comprising a housingcontaining at least one spherical roller, said at least one sphericalroller adapted to contact a generally planar surface for supporting thepiece of furniture, the caster having a plurality of spherical ballslocated intermediate said at least one spherical roller and saidhousing, said spherical balls adapted to move in a continuouscirculatory path within said housing and to enter the area intermediatesaid at least one spherical roller and said housing by means of gravity,wherein said at least one spherical roller is freely rotatable underload to allow movement of the piece of furniture in any direction; andaffixing the housing of the caster within the recessed area of thefurniture leg.
 10. The method of claim 9 wherein the step of forming arecessed area comprises molding a recessed area in the lower end of aplastic furniture leg.
 11. The method of claim 9 wherein the step offorming a recessed area comprises cutting a recessed area in the lowerend of a wooden furniture leg.
 12. The method of claim 9 wherein thestep of affixing the caster within the recessed area comprises affixingthe caster so as to substantially enclose the caster housing within therecessed area.
 13. The method of claim 9 wherein the step of providing acaster comprising a housing containing at least one spherical rollercomprises providing a caster comprising a housing containing threespherical rollers having center points forming a equilateral triangle.14. A leg member that elevates a piece of furniture above a generallyplanar surface, said leg member having an upper surface having a wedgemember extending upwardly therefrom, said wedge member being configuredto fit into a corresponding shaped receptacle formed in the piece offurniture.
 15. A leg member as defined in claim 14 wherein said wedgemember has an upper end and comprises a pair of straight portionsmeeting at an angle and having external edges.
 16. A leg member asdefined in claim 14 wherein the receptacle has internal edges that areinwardly tapered and said external edges of said wedge member taperinwardly toward said upper end.
 17. A leg member as defined in claim 14wherein the wedge member is constructed of wood, plastic or metal.
 18. Aleg member as defined in claim 14 wherein the leg member contains aunidirectional caster.
 19. A piece of furniture having a lower surface,a receptacle formed in said lower surface, said piece of furniturehaving a caster assembly affixed thereto, said caster assembly having awedge member dimensioned to interfit into the receptacle, said malewedge member being forcefully jammed into the receptacle to retain thecaster assembly to said piece of furniture.
 20. A piece of furniture asdefined in claim 19 wherein the piece of furniture is a box spring. 21.A piece of furniture as defined in claim 19 wherein the receptacle hasinternal edges that are inwardly tapered and said wedge member hasexternal edges that taper inwardly generally corresponding to the inwardtaper of said receptacle.
 22. A piece of furniture as defined in claim19 wherein said wedge member is a generally L-shaped configuration.